A population of 455 critically endangered white-cheeked crested gibbons were found in Pu Mat National Park in Vietnam's central Nghe An province, the Conservation International (CI) statement said.

According to Vietnam News Agency on Wednesday, the community, which was found living at high altitudes and far from human settlements on the border with Laos, represents two thirds of the total number in Vietnam and the "only confirmed viable population" of the variety worldwide.

Gibbons, threatened across the world, are considered the "most romantic" of primates as they mate for life and serenade their partners with song.

Habitat loss, hunting for the pet trade and the "assumed medicinal value of primate body parts," are among the major threats to the creatures in Vietnam. The species are described as "on the brink of extinction", the CI statement said.

According to the International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species, white- cheeked gibbon numbers are thought to have declined by as much as 80 percent in the last 45 years. They are believed to be "functionally extinct" in China, and while there could be significant numbers in Laos, the situation is unclear due to a lack of research.